Formula mom here. She will very likely self regulate, especially if she's also getting breast milk. Your milk will shift based on her nutritional needs. You may want to consider pumping when she formula feeds if you have any concerns about possible supply issues. My kid was a low volume snacker. She'd take 80-100, sometimes 120 mL feeds generally. Age also makes a difference. After the 3 month growth spurt, amounts tend to level out, although not always. I wouldn't worry too much about the guidelines, as long as she is growing well and generally feeding, you should be fine.
She's 16 weeks 😊
How old is she? The guide on the tin is purely just a guide, she is also getting breast milk so try not to worry x